The purpose of the National HIV Behavioral Surveillance (NHBS) system is to examine the prevalence of risk behaviors antecedent to human immunodeficiency virus (HIV) acquisition in a population-based, representative sample of individuals in areas with high HIV/AIDS rates. Washington, DC has the highest prevalence of newly reported AIDS cases of states and territories, with 128 cases per 100,000 in 2005; it ranks third among metropolitan areas. Heterosexual contact is the most frequently reported mode of transmission (31%), followed by men who have sex with men (MSM) (27%), and injection drug use (IDU) (18%). The Department of Health/HIV/AIDS Administration (DOH/HAA) and George Washington University (GWU) formed a Public Health/Academic Partnership to successfully implement NHBS-HET-1, meeting accrual goals with the highest regard for human subjects protection, protection of surveillance data, and community involvement; DOH/HAA will continue the Partnership with GWU to conduct NHBS-2. Other Partnership accomplishments of public health importance include collaborations among DOH/HAA and GWU faculty and staff, community members, MPH students, and bilingual interviewers; development of positive and effective community relationships with local HIV care organizations, community advocacy groups, neighborhood councils, and prevention agencies; development of an active Community Advisory Board. The Partnership provides a unique opportunity for the training and professional development of the current and next generation of public health professionals. In the proposed study for NHBS-2, three serial cross-sectional studies will be conducted, focusing on MSM, IDU, and heterosexuals at high risk for HIV infection (HET) in annual succession. For each data collection year, following Institutional Review Board approval, an extensive qualitative evaluation including an ethnographic assessment and secondary data review will be conducted to inform culturally competent and effective methods for study implementation. A minimum of 500 participants for each study year will be recruited using either venue-based, time and space sampling or respondent-driven sampling; survey implementation and HIV testing will be conducted by trained staff in fixed and mobile sites. HIV seroprevalence, risk, and testing behavior data will be forwarded to CDC monthly. Rapid analysis and dissemination of data will inform our understanding of behavior among residents of the metropolitan Washington, DC area as well as prevention strategies. Through the District's participation in NHBS-2, we will together meet the Healthy People 2010 objectives, and contribute to the public health and welfare overall. [unreadable] [unreadable] [unreadable]